Two Tennessee girls missing since their mother and sister were murdered were rescued today in Mississippi, where their suspected abductor apparently shot himself to death, an FBI official said.

"The girls were found alive and appear to be unharmed," Daniel McMullen, the FBI special agent in charge for the state of Mississippi, told reporters. "Officers also apprehended top-10 fugitive Adam Mayes. Preliminary reports indicate Mayes shot himself in the head and was later pronounced dead in an area hospital."

Units with the Mississippi Highway Patrol rescued Alexandria and Kyliyah Bain, ages 12 and 8, and found Mayes, 35, suspected of abducting them and killing their mother and sister, in a wooded area a few miles from his home in Union County, Miss., sources said. Mayes was treated in an ambulance at the scene of his shooting and taken to a hospital around 7 p.m.

Though the girls appeared to be unharmed, they were taken to a hospital as a precaution, McMullen told reporters in Guntown, Miss., the town where Mayes lived.

Mayes' ex-mother-in-law earlier said she believed Mayes killed the girls' mother and her eldest daughter, and then ran away with the two girls because he believed the girls were his own children.

Josie Tate, the mother of Mayes' ex-wife, Teresa Mayes, told ABC News affiliate WTVC that her daughter and Mayes fought often over whether Mayes was actually the father of JoAnn Bain's two youngest children.

Bain and her eldest daughter, Adrienne, were killed in their Tennessee home on April 27, and then taken with the two youngest daughters to Mayes' home in Mississippi, according to police affidavits. Teresa and Adam Mayes had both been charged with murder.

After the killings of JoAnn and Adrienne Bain, the FBI put Mayes on its Top Ten Most Wanted fugitives list.

"The reasons they were arguing so much was because there were two little girls that he was absolutely obsessed with. He was claiming those two children were his," Tate told WTVC.

Neighbors told a similar story, that Mayes was a close family friend of the Bain family and told people that he was the father of the two youngest girls.

"He made us all think that was his kids," Andrea Miller, a neighbor and friend of Adam Mayes, told WTVC.

FBI officials have said they believe Bain was preparing her family to move to Arizona at the end of the school year. The family had ties to Arizona, where the two older daughters were enrolled in school on and off between the years 2004 and 2009, according to the Tucson citizen.

Police said at a press conference Tuesday that Bain's husband, Gary Bain, was grieving for JoAnn, his ex-wife, and Adrienne, but hopeful about bringing the other two girls home.

"We will hunt down Adam Mayes and rescue those two little girls," said FBI Special Agent Aaron Ford at the press conference.

On Tuesday, Teresa Mayes and Adam Mayes' mother, Mary, were arrested and charged with 'especially aggravated kidnapping.' According to the warrants, Teresa Mayes told police she witnessed Adam kill JoAnn Bain in the garage of the Bain's home, and then kill Adrienne Bain in the home itself.

Adam and Teresa Mayes then took the dead bodies and two young girls to the Mayes' home in Mississippi, where Adam Mayes allegedly buried the two bodies, the documents state.

The bodies of mother and daughter were found earlier this week in the backyard of the home Mayes shares Teresa and his mother and father.

Manhunt for Adam Mayes

Before the girls were found, the FBI warned that Mayes may have changed his appearance and the appearances of the two girls since they were last seen.

Police located a trailer that Mayes had rented from Union County, Miss., that contained items belonging to the two girls, the documents state.

Mayes was last seen on April 30, in surveillance video from a grocery market in Guntown, Miss., where he lives. Police have also found a trailer Mayes rented from Guntown that contained personal items belonging to the two young girls.

Authorities were offering a $71,000 reward for information leading to Adam Mayes' whereabouts and arrest, including $6,000 from the Tennessee Bureau of Investigation, $50,000 from the FBI and U.S. Marshals Service, and $15,000 from the Tennessee governor's office.